In Vitro Fertilization (IVF) is a common procedure in animals and humans to increase the likelihood of pregnancy and/or to control certain aspects of a pregnancy. For example, in the case of animals such as cattle, IVF may be used to control the genetics of the offspring and thus the future makeup (e.g., gender ratio) of the herd. IVF may also be used to ensure that future offspring have the optimum characteristics for the production of either meat or milk. Thus, semen for use in IVF procedures may be selected based on desired offspring traits such as fast growth rate, high milk production, better overall health, and adaptations for the local climate.
In animals, the IVF process has to be performed by a skilled professional and is a time-consuming and intensive procedure for each animal. Accordingly, it would be beneficial to increase the success rate of these procedures, such that the valuable sperm and the time commitment from these professionals are most effectively used.
One of the factors influencing the success of any IVF procedure is the timing of insemination relative to the estrous cycle of the animal. Various biological changes take place within the animal that can influence the success of the IVF procedure. In order to ensure that these IVF procedures are carried out at a correct time, two main methods of estrous cycle monitoring/manipulation have emerged.
The first method aims to manipulate the natural estrous cycle of the animal such that the ideal insemination time can be predicted. A series of drugs are delivered to the animal(s) over the course of 10-14 days that force the reproductive cycle into a predictable pattern. This method allows the entire herd to be put onto the same cycle and therefore gives the ranch the ability to consolidate IVF procedures.
Another method involves attempting to monitor an animal's behavior and/or physiological symptoms in order to predict the cycle of an animal, such that insemination can be performed at an ideal time. For example, products are available that can be attached to an animal's back to detect “mounting events” (i.e., when cattle mount each other before becoming fully in heat), temperature, or activity. Vaginal tissue temperature or conductivity measurements may also be taken manually by ranch personnel.
These known products and procedures typically have a very high false positive rate. For example, temperature sensors are often triggered by changes in the environment, health, or activity of the animal, mounting detectors can be triggered by rubbing against trees and do not have very good resolution, and internal conductivity measurements have to be conducted manually and therefore can only be performed intermittently. While these products and procedures have shown some success in increasing pregnancy rates, data varies considerably depending on the way in which the product is implemented. Accordingly, there is a need for improved estrus sensing devices, methods, and systems that can be used to improve pregnancy rates in animals and groups of animals, such as cattle.
In humans, IVF is primarily used in cases where normal reproduction has not been successful. Human IVF procedures are extremely expensive and a failure can be emotionally devastating for those involved. While humans are more capable of measuring various biological factors (e.g., temperature) manually, it would also be desirable for women to have improved fertile window detection capabilities in order to increase the chance of pregnancy.
Accordingly, there is a need for improved estrus detection devices, systems, and methods that provide accurate estrous cycle monitoring and reduce the occurrence of false positives.